In quality testing of mass products it is often necessary to perform tightness tests. Thus, washing machines and dish washing machines have to be tested to detect possible leaks in hoses and pipes.
DE 10 2007 032 250 B3 describes a device for detecting liquid leaks, comprising a large-surface, electrically non-conductive surface element on which conductor paths are provided. An electric voltage is applied to the conductor paths. By measuring the electric resistance, it is detected whether a drop of liquid is on the surface element.